Epidermal Cyst
(Epidermoid Cyst; Epidermal Inclusion Cyst; Epithelial Cyst; Keratin Cyst; Sebaceous Cyst)
Definition
An epidermal cyst is a firm, slow-growing lump underneath the skin. This cyst contains soft, cheesy-like skin secretions. These usually appear on the scalp, face, neck, chest, upper back, genitals, or behind the ears.
Causes
Causes include:
- Blockage of a hair follicle by skin cells—When an injury to the skin occurs, cells from the surface may block hair follicles located deeper within the skin.
- Damage to a hair follicle due to acne
- Blockage or defect of the sebaceous gland—This gland is near the hair follicle. It secretes oily material used to lubricate the skin and hair.
Hair Follicle

Symptoms
If you have any of these symptoms do not assume it is due to a cyst. These symptoms may be caused by other conditions. Tell your doctor if you have any of these:
- Small, dome-shaped lump beneath the skin
- Foul-smelling, cheesy-like material draining from the cyst
- Redness or tenderness on or around the cyst if it becomes inflamed
Diagnosis
Your doctor will ask about your symptoms and medical history, and perform a physical exam. In most cases, the diagnosis can be made by looking at it. You may be referred to a dermatologist, a doctor who specializes in skin disorders.
Treatment
Talk with your doctor about the best treatment plan for you. Treatment options include the following:
- Surgical excision—The doctor removes the entire cyst, including its contents and cyst wall.
- Surgical drainage—This involves cutting open the cyst, draining the contents, and removing the cyst wall. The cyst might come back, though.
- Steroid injection—This involves injecting steroids into the cyst to reduce inflammation. The cyst is not removed, though.
- Antibiotics—These may be prescribed to reduce the risk of an infection after surgery or drainage.
If you are diagnosed with an epidermal cyst, follow your doctor's instructions .
RESOURCES:
American Academy of Dermatology
http://www.aad.org/
American Academy of Family Physicians
http://www.aafp.org/
CANADIAN RESOURCES:
Canadian Dermatology Association
http://www.dermatology.ca/english/
Dermatologists.ca
http://www.dermatologists.ca/index.html/
References:
Common benign cutaneous growths: seborrheic keratoses, cherry hemangiomas, and epidermal cysts. American Academy of Dermatology website. Available at: http://www.aad.org/professionals/Residents/MedStudCoreCurr/DCBenignCutaneousG.htm . Accessed September 4, 2005.
Cysts. DermNet NZ website. Available at: http://dermnetnz.org/lesions/cysts.html . Updated March 2008. Accessed June 17, 2008.
Freedberg IM, Eisen AZ. Fitzpatrick’s Dermatology in General Medicine. Vol 1. 5th ed. New York, NY: McGraw-Hill Health Professions Division; 1999: 884-885.
Habif TP. Habif’s Clinical Dermatology . 4th ed. St. Louis, MO: Mosby; 2004.
Odom RB, James WD. Andrews’ Diseases of the Skin: Clinical Dermatology. 9th ed. Philadelphia, PA: WB Saunders Company: A Harcourt Health Sciences Company; 2000: 862-863.
Sebaceous cyst. National Library of Medicine, Medline Plus website. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000842.htm . Updated April 2007. Accessed September 2, 2005.
Zuber TJ. Minimal excision technique for epidermal (sebaceous) cysts. American Family Physician . 2002;65:1409-1412.
Last reviewed November 2008 by Ross Zeltser, MD, FAAD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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